Oprah Winfrey is quitting her show for her BFF Gayle King – and they’re moving in together!

That’s the shocking story behind the talk-show queen’s surprise announcement that she’s abdicating her TV throne in 2011 after 25 years on the air.

The move will also mark the end of Oprah’s longtime relationship with Stedman Graham, sources say, as the 55-year-old media mogul focuses her attention on grooming Gayle for her own talk show on the Oprah Winfrey Network (OWN) and other projects for the two of them.

As part of her plan, Oprah intends to move Gayle into "The Promised Land," her sprawling 42-acre estate in Montecito, Calif., which she’s told pals will be her primary residence.

"Now that she’s giving up her talk show, Oprah sees no reason to stay in Chicago," said a TV insider close to Winfrey.

"She was planning on making the transition to the Southern California area anyway, for the sake of her Oprah Winfrey Network.

"She and Gayle have a number of good friends in the Santa Barbara area, and they feel like it’s home. They both love it there."

Oprah’s move to California with Gayle, 54, will also mark the end of her relationship with 58-year-old Stedman, the public relations and marketing executive she began dating in May 1986.

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